1. Technical Field
The present invention relates to a display apparatus, a display method, and a program.
2. Related Art
When the neural circuit in the brain is damaged due to a stroke, limbs are paralyzed in some cases. Methods that allow such a patient to undergo rehabilitation have been invented. One of the methods causes the patient to think that the patient should attempt moving a paralyzed limb and shows the patient images in which the paralyzed limb is moving so that the patient has a feeling as if the limb were moving.
A patient whose limb has been lost due, for example, to an accident sometimes has a painful sensation in the limb. The phenomenon is called a phantom pain. A method similar to the method described above has been proved to be effective for such a patient. In the method, an image that causes the patient to have a feeling as if the lost limb existed is shown to the patient. The method allows appropriate recognition of the lost limb in the brain of the patient to eliminate or alleviate the pain.
JP-A-2004-298430 discloses an apparatus that causes a patient to visually recognize as if a paralyzed hand or a lost hand were moving. According to JP-A-2004-298430, a plurality of magnetic sensors are attached to the body of the patient. A predetermined magnetic field is then applied to the patient, and the posture of the patient is detected. Motion images of the hand are then displayed on a display apparatus. In this process, the hand in the motion images is so adjusted in terms of position, posture, and size as to unite with the patient.
The patient who sees the motion images has a feeling as if the hand in the motion images were part of the body of the patient. The patient whose hand has been lost re-experiences a sense of unity of the hand in the brain, resulting in elimination or alleviation of the pain of the hand. In a case of a patient whose hand is paralyzed, the neural circuit is reconstructed in the brain, whereby the paralysis of the hand is alleviated.
In JP-A-2004-298430, the motion images to which the patient refers are images generated by an image generator. The images are animation images generated by a computer. Since the images are generated in real time, it is believed that the motion images are not formed of realistic images but are simplified images formed of polyhedrons. Further, JP-A-2004-298430 suggests that captured images are used, but it is believed in this case that the captured images are motion images that are not synchronized with the motion of the patient.
When a patient keeps conducting training, the neural circuit in the brain is reconstructed. It has been proved that for a patient who is not accustomed to training, motion images are preferably slowly displayed and a long standby period is preferably set when the action in the images changes. JP-A-2004-298430 suggests that the apparatus described therein has a mode in which animation images are used and a mode in which captured images are used. When animation images are used, they are images different from an actual body part and make it difficult for the patient to concentrate on training. Further, when the method does not fit the patient, the training is unlikely to be effective. As a method for conducting training, there is a training method that causes a patient to follow captured images as guidance to move a lost site or a paralyzed site. There is further an effective method that causes a patient to use a mirror and follow images showing motion of a normal body part as guidance. It has been desired to provide a display apparatus that allows a patient to efficiently conduct training by using a plurality of motion images that fit the patient's own training.